1. Field of the Invention
The present invention relates to breakout cables and, more particularly, to breakout cables having a large number of optical fibers.
2. Description of the Prior Art
Breakout cables utilized for wiring premises, such as apartments and commercial buildings, are subject to a number of different stresses during installation. These stresses include longitudinal stresses caused by pulling the breakout cables through plenums and risers, transverse stresses due to bending of the cables around corners, environmental stresses, and other stresses known to those skilled in the art.
Prior art optical fiber breakout cables include a cylindrically-shaped elongated outer sheath for receiving the plurality of optical fibers therein. A problem with utilizing a cylindrically-shaped elongated outer sheath is the need to provide space between jackets that surround groups of optical fibers received within the outer sheath. The need to provide this space results in an undesirable increase in the diameter of the breakout cable.
It is, therefore, an object of the present invention to overcome the above problem and others by providing an optical fiber breakout cable having a low profile. It is another objective of the present invention to provide an optical fiber breakout cable having a small bend radius. Still other objects of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description.
Accordingly; an optical fiber breakout cable has been invented that includes a plurality of optical fiber ribbon cables arranged in an array having at least two columns and at least two rows. Each optical fiber ribbon cable includes a first jacket and may include a second jacket surrounding a plurality of optical fibers arranged in an array having at least one row. At least one row of each optical fiber ribbon cable is positioned parallel to the rows of the array of optical fiber ribbon cables. An outer sheath surrounds the array of optical fiber ribbon cables. The outer sheath has a top surface and a bottom surface in spaced parallel relation and a pair of outward facing sides. The distance between the top surface and the bottom surface of the outer sheath is less than the distance between the pair of outward facing sides of the outer sheath.
The optical fiber breakout cable can include a plurality of elongated strength members. Preferably, each strength member is positioned between a side of the array of optical fiber ribbon cables and one of the sides of the outer sheath, and between adjacent rows of optical fiber ribbon cables. Preferably, the first jacket is formed from an aramid material, and the second jacket and sheath are formed from polyvinyl chloride (PVC) or polyvinyl difluoride (PVDF). Each strength member is formed from an aramid material. Other various materials with flame retardant capabilities may be used for the jackets or sheath.
The second jacket, if used, surrounds the first jacket. The second jacket can have a top surface and a bottom surface in spaced parallel relation and a pair of outward facing sides. The distance between the top surface and the bottom surface of the second jacket is less than the distance between the pair of outward facing sides of the second jacket.
Preferably, the outer sheath, the first jacket, and the second jacket have oval cross-sections.